How do I use quick data entry to Scale to the 3D Cursor when using Normal Transformation Orientation?
You simply have to press the axis key (X, Y or Z) twice when performing the transformation.

For example, pressing S, Z, Z, 0 will scale everything to 0 along the 'Z' normal axis if 'Normal' transformation type is selected in the 3D view header:



Basically whatever transformation is selected in the header will be switched to when pressing the axis key twice.